[exim-cvs] wip

Gitweb: https://git.exim.org/exim.git/commitdiff/143b1159402424b930881bc8d25c640f1d6cd581

Commit:     143b1159402424b930881bc8d25c640f1d6cd581
Parent:     8e61d2807317ed66163a395c1cd8666fd442d9aa
Author:     Jeremy Harris <jgh146exb@???>
AuthorDate: Wed May 5 20:14:47 2021 +0100
Committer:  Jeremy Harris <jgh146exb@???>
CommitDate: Wed May 5 22:04:13 2021 +0100

    wip
---
 src/src/dns.c    | 14 ++++++++++----
 test/stderr/0277 |  8 ++++----
 test/stderr/0469 |  2 +-
 test/stderr/2202 |  4 ++--
 4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/src/dns.c b/src/src/dns.c
index c686987..217fe5f 100644
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -691,9 +691,11 @@ packet length has been lost inside libresolv, so we have to guess a
replacement value. (The only way to fix this properly would be to
re-implement res_search() and res_query() so that they don't muddle their
success and packet length return values.) For added safety we only reset
-the packet length if the packet header looks plausible. */
+the packet length if the packet header looks plausible.

-static void
+Return TRUE iff it seemed ok */
+
+static BOOL
 fake_dnsa_len_for_fail(dns_answer * dnsa, int type)
 {
 const HEADER * h = (const HEADER *)dnsa->answer;
@@ -710,7 +712,11 @@ if (  h->qr == 1                /* a response */
   DEBUG(D_dns) debug_printf("faking res_search(%s) response length as %d\n",
     dns_text_type(type), (int)sizeof(dnsa->answer));
   dnsa->answerlen = sizeof(dnsa->answer);
+  return TRUE;
   }
+DEBUG(D_dns) debug_printf("DNS: couldn't fake dnsa len\n");
+/* Maybe we should just do a second lookup for an SOA? */
+return FALSE;
 }

@@ -724,7 +730,7 @@ dns_expire_from_soa(dns_answer * dnsa, int type)
{
dns_scan dnss;

-fake_dnsa_len_for_fail(dnsa, type);
+if (!fake_dnsa_len_for_fail(dnsa, type)) return 0;

 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY);
      rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
@@ -1201,7 +1207,7 @@ switch (type)

     if (rc == DNS_NOMATCH)
       {
-      fake_dnsa_len_for_fail(dnsa, T_CSA);
+      if (!fake_dnsa_len_for_fail(dnsa, T_CSA)) return DNS_NOMATCH;

       for (rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY);
        rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
diff --git a/test/stderr/0277 b/test/stderr/0277
index 1c81cc7..0cbd2a9 100644
--- a/test/stderr/0277
+++ b/test/stderr/0277
@@ -18,7 +18,7 @@ looking up host name for V4NET.2.3.4
 DNS lookup of 4.3.2.V4NET.in-addr.arpa (PTR) using fakens
 DNS lookup of 4.3.2.V4NET.in-addr.arpa (PTR) gave HOST_NOT_FOUND
 returning DNS_NOMATCH
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for 4.3.2.V4NET.in-addr.arpa-PTR-xxxx, ttl -1
 LOG: host_lookup_failed MAIN
   no host name found for IP address V4NET.2.3.4
@@ -96,7 +96,7 @@ looking up host name for V4NET.10.11.12
 DNS lookup of 12.11.10.V4NET.in-addr.arpa (PTR) using fakens
 DNS lookup of 12.11.10.V4NET.in-addr.arpa (PTR) gave HOST_NOT_FOUND
 returning DNS_NOMATCH
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for 12.11.10.V4NET.in-addr.arpa-PTR-xxxx, ttl -1
 LOG: host_lookup_failed MAIN
   no host name found for IP address V4NET.10.11.12
@@ -141,7 +141,7 @@ looking up host name for V4NET.1.1.1
 DNS lookup of 1.1.1.V4NET.in-addr.arpa (PTR) using fakens
 DNS lookup of 1.1.1.V4NET.in-addr.arpa (PTR) gave HOST_NOT_FOUND
 returning DNS_NOMATCH
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for 1.1.1.V4NET.in-addr.arpa-PTR-xxxx, ttl -1
 LOG: host_lookup_failed MAIN
   no host name found for IP address V4NET.1.1.1
@@ -186,7 +186,7 @@ looking up host name for V4NET.2.2.2
 DNS lookup of 2.2.2.V4NET.in-addr.arpa (PTR) using fakens
 DNS lookup of 2.2.2.V4NET.in-addr.arpa (PTR) gave HOST_NOT_FOUND
 returning DNS_NOMATCH
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for 2.2.2.V4NET.in-addr.arpa-PTR-xxxx, ttl -1
 LOG: host_lookup_failed MAIN
   no host name found for IP address V4NET.2.2.2
diff --git a/test/stderr/0469 b/test/stderr/0469
index 3401ded..f3b5593 100644
--- a/test/stderr/0469
+++ b/test/stderr/0469
@@ -24,7 +24,7 @@ DNS lookup of mxt1c.test.ex (MX) succeeded
 DNS lookup of dontqualify (A) using fakens
 DNS lookup of dontqualify (A) gave NO_DATA
 returning DNS_NODATA
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for dontqualify-A-xxxx, ttl -1
 fully qualified name = mxt1c.test.ex
 host_find_bydns yield = HOST_FIND_FAILED (0); returned hosts:
diff --git a/test/stderr/2202 b/test/stderr/2202
index e936b5e..a7c78ea 100644
--- a/test/stderr/2202
+++ b/test/stderr/2202
@@ -42,7 +42,7 @@ DNS lookup of cioce.test.again.dns (MX) using fakens
 DNS lookup of cioce.test.again.dns (MX) gave TRY_AGAIN
 cioce.test.again.dns in dns_again_means_nonexist? yes (matched "*")
 cioce.test.again.dns is in dns_again_means_nonexist: returning DNS_NOMATCH
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for cioce.test.again.dns-MX-xxxx, ttl -1
  creating new cache entry
  lookup failed
@@ -65,7 +65,7 @@ DNS lookup of cioce.test.again.dns (A) using fakens
 DNS lookup of cioce.test.again.dns (A) gave TRY_AGAIN
 cioce.test.again.dns in dns_again_means_nonexist? yes (matched "*")
 cioce.test.again.dns is in dns_again_means_nonexist: returning DNS_NOMATCH
-DNS: no SOA record found for neg-TTL
+DNS: couldn't fake dnsa len
  writing neg-cache entry for cioce.test.again.dns-A-xxxx, ttl -1
 host_fake_gethostbyname(af=inet) returned 1 (HOST_NOT_FOUND)
 no IP address found for host cioce.test.again.dns (during SMTP connection from the.local.host.name [ip4.ip4.ip4.ip4])